What is HD-AVS?

 

Overview

---

IC Realtime's High Definition Advanced Video System (HDAVS) technology is an HD-over-coaxial cable video standard that allows long-distance, HD transmission of video, audio, and control functions.

With average transmission distances of 1500' over RG59 coaxial cable, and now even higher definition capabilities, including 720P, 1080P, & 4MP options, HDAVS is the ideal technology for upgrading existing installations to current video quality standards.

IC Realtime's latest HDAVS Recorders (HDAVRs) are compatible with the five major technologies available in today’s video surveillance market (standard analog, IP, HDAVS, HDTVI and AHD). The industry has progressed from 'hybrid' (regular analog & IP) to 'tribrid' (regular analog, HDAVS, and IP), to now 'penta-brid'.

Benefits

---

One big advantage of HDAVS, compared to other analog systems, is the transmission distance. With average transmission distances of 1500' and a low signal distortion rate, you can reach further distances, with higher quality video, than standard analog systems.

Updating existing installations has never been easier. Simply use the existing cable for video, audio, & the control signals. The required infrastructure is also more forgiving, allowing for lower cable quality, cable joints, and use of unshielded twisted pair cable.

Technical Info

---

HDAVS chipsets consist of a transmitting chip and receiving chip. Operating in a star topology, the DVR serves as a node for point-to-point transmission to cameras over coaxial cabling. HDAVS uses the analog base band and quadrature modulation technology, which is an analog modulation scheme. It conveys three analog message signals (Y,U,V), by changing (modulating) the phases of two carrier waves, using the quadrature modulation technology and amplitude modulation analog scheme.

With Auto Signal Compensation (ASC) incorporated, HDAVS achieves extremely low signal distortion over long-distance transmission. Both forward and reverse data channels are combined in the frame-blanking area, which enables a two-way end-to-end transmission that supports camera command controls, such as camera focus, PTZ control, real-time alarm, etc. Forward outputting data supports a high-transmission baud rate, as the time and electric signal baud rate to the camera is predictable, and the receiving direction uses high-ASC.

Reverse output data supports a lower baud rate due to its limited data and low signal frequency, which are affected by impedance matching and channel transmission uncertainty. Adopting ASC, the reverse channel restores some degree of electrical signal during long-distance transmission. Both audio and two-way data communication signals are embedded in a blanking zone, which enhances synchronization with the video system and supports a maximum sampling rate of 44.1 kHz.